Sleep
Sleep Guides
Better rest, cycles, and recovery, backed by research.
- Sleep
How Much Caffeine Is Too Much in a Day?
Learn what 400 mg of caffeine per day really means, how to total coffee and energy drinks, and when a lower limit may be wiser. - Sleep
What Time Should You Go to Bed? Sleep Cycles Explained
Learn how sleep calculators estimate bedtimes using 90-minute cycles, why sleep stages vary, and how to plan enough sleep without chasing a perfect alarm time. - Sleep
How Long Should You Nap? Best Length and Timing
Learn how long a nap should last, compare 10–20 minutes with 90 minutes, and understand sleep inertia, timing, and the limits of nap timers. - Sleep
How Much Sleep Debt Do You Have? Recovery Guide
Calculate your weekly sleep deficit, understand why recovery is not hour-for-hour, and learn practical ways to improve sleep without relying on weekend catch-up. - Sleep
How Does Blue Light Affect Sleep? Your Evening Habits Score
Learn how blue-rich evening light relates to circadian rhythms, what a screen-habits score means, and which sleep-friendly changes are supported by evidence. - Sleep
Sleep Chronotypes: Are You a Lion, Bear, Wolf, or Dolphin?
Lion, Bear, Wolf, or Dolphin? Your chronotype is your body’s natural timing — and matching your day to it makes sleep and focus easier. - Sleep
The Best Time to Stop Drinking Coffee for Better Sleep
Caffeine lingers for hours. Research shows even an afternoon coffee can steal sleep. Here is how to set a sensible caffeine curfew.